feat(lab): add check-x icon (#4737)

* feat(icons): add check-x icon (#4130)

* Move check x to lab

* fix(lab): add missing use-cases array to lab/check-x.json

* Add use cases for notifications in check-x.json

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: ishanbagra18 <your-email@example.com>
Co-authored-by: Eric Fennis <eric.fennis@gmail.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

lab/check-x.json

@@ -0,0 +1,23 @@
+{
+  "$schema": "../icon.schema.json",
+  "contributors": [
+    "ishanbagra18"
+  ],
+  "tags": [
+    "uncheck",
+    "cancel",
+    "remove",
+    "unread",
+    "cross",
+    "mark",
+    "deselect",
+    "task"
+  ],
+  "categories": [
+    "notifications"
+  ],
+  "use-cases": [
+    "Unmarking / toggling read status (mark unread / uncheck)",
+    "Task & checklist management (cancel/reject a checked item)"
+  ]
+}

lab/check-x.svg

@@ -0,0 +1,15 @@
+<svg
+  xmlns="http://www.w3.org/2000/svg"
+  width="24"
+  height="24"
+  viewBox="0 0 24 24"
+  fill="none"
+  stroke="currentColor"
+  stroke-width="2"
+  stroke-linecap="round"
+  stroke-linejoin="round"
+>
+  <path d="M16 6 7 15l-3-3" />
+  <path d="m14 14 6 6" />
+  <path d="m20 14-6 6" />
+</svg>